The present invention relates to improved dental stock trays for taking an impression of a dentulous or edentulous mouth, particularly to the ones used for the following purposes: in general dental treatment, manufacturing a complete denture, a partial plate denture, a crown restoration or a treatment apparatus for a periodontal disease; in pediatric dentistry, manufacturing a complete denture, a partial plate denture or a crown restoration; in orthodontics, manufacturing an orthodontic appliance; manufacturing an apparatus for surgically treating a mouth including a temporomandibular joint; manufacturing a mouthpiece used in hard sports, such as boxing, karate, judo, soccer, football and baseball; during research in legal medicine or criminal investigation, collecting data or evidence thereof; manufacturing a mouthpiece used in eating or drinking and removed thereafter for deodorization or prevention of tooth decay; manufacturing a mouthpiece used in singing, playing a wind instrument or practicing pronunciation; or treating teeth of an animal.
Moreover, the present invention relates to improved stock trays used in taking an impression for fabricating an apparatus to be installed in a mouth of a subject when a maker of foods, drugs or spices develops a product such as vitamin compound, nutrient, drug, spice and sweetener. This apparatus comprises a chamber with a semipermeable fine mesh membrane made of plastic or metal. The chamber may be attached to the inner side of an artificial tooth or a plate of a denture, or to a hidden area in a mouthpiece. The chamber may be provided at an edge position of a plate in a denture or mouthpiece. When the denture or mouthpiece is inserted in a mouth, the edge position faces a maxillary tuberosity in the case of maxilla (thus a parotid gland for providing saliva is open near the position), or faces a sublingual caruncle in the case of mandible (thus a sublingual gland for providing saliva is open near the position). Previously, a predetermined amount of molten material such as vitamin compound, nutrient, drug, spice and sweetener is stored in the chamber. Osmotic pressure disperses the material into saliva with passing time. The effects in keeping and improving the subject's health may be investigated on the base of the pre-calculated amount to be ingested in a day.
In prior art dentistry, taking an impression is carried out twice in a process of manufacturing a denture: a preliminary impression of a mouth is taken with a "stock tray" to manufacture an "individual tray" first, and then a precise impression is taken with the individual tray to make a model of the mouth. The denture is manufactured by use of the model.
Historically such stock trays for taking preliminary rough impressions of mouths were devised about the middle of the 19th century on the basis of dental knowledge in those days. The materials of the stock trays have been replaced with metal or plastic, but their shapes have been hardly improved up to now.
In many cases, the preliminary impression taken with a conventional stock tray becomes inaccurate at some key parts, which adversely affects substantially the precise impression taken with an individual tray. As a result, a denture not satisfactory to a dentist may be obtained thereby giving a patient a pain. Such situation may occur in the case of a complete denture or partial plate denture.